WO1987005165A1

WO1987005165A1 - Switching regulator

Info

Publication number: WO1987005165A1
Application number: PCT/JP1987/000118
Authority: WO
Inventors: Naoto Ota
Original assignee: Fanuc Ltd
Priority date: 1986-02-24
Filing date: 1987-02-23
Publication date: 1987-08-27
Also published as: US4809151A; KR880701034A; JPS62196071A; EP0257101A1; EP0257101A4

Abstract

In a DC-DC converter using an inverter, a series circuit consisting of a primary winding (N41) of a main power source transformer (T4), a first diode (45) and a switching means (2) is connected to a DC power source (1), and the primary winding (N51, N61) of at least one auxiliary transformer (T5, T6) and a second diode (55, 65) correspondent are connected in a parallel with a series circuit consisting of the primary winding (N41) of the main power source transformer (T4) and the first diode (45). Thus, a chopped voltage is applied to a plurality of transformers simultaneously by using a single switching control circuit (3) and a single switching means (2), so that a plurality of DC voltages can be outputted being insulated from each other.

Description

Technical field of fine switching regulator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching regulator, and more particularly to a switching regulator for driving a power device that requires a plurality of DC power sources that are mutually isolated. Background technology

Conventionally, a power source that outputs a plurality of DC power sources that are mutually isolated from one input power source, for example, an inverter device for an unmanned vehicle (AGV) that drives an AC servomotor using a battery as a power source, etc. A switching regulator is used in consideration of the power source, weight, efficiency and occupied volume.

This conventional switching regulator uses a switching control circuit and a switching transistor to apply a chopping voltage to a single transformer to produce the required multiple DC voltages. ..

By the way, the AC servo motors that do not require brushing and are advantageous in terms of maintenance are mainly used as the motors used for the AGV drive motors and lift devices. In order to drive and control this AC servo motor, in addition to the main power supply required for the main control circuit, the main power supply and an abandoned drive power supply are required. This drive power supply is the power supply for the moving part (driver) that amplifies the signal of the control circuit to drive the large-capacity power transistor in order to supply the controlled power supply to the AC servo motor. The power supply for the driver must not only be isolated from the control circuit, but also the power supply for each driver must be insulated from each other. And, when driving and controlling one AC servomotor with three-phase AC, for example, six sets of mutually isolated driver power supplies are required to control with six driver transistors. ..

As mentioned above, conventional switching regulators use one switching control circuit and switching transistor, and apply the chopped voltage to one transformer to obtain the required voltage. And you have the required number of DC power supplies. That is, when one AC servomotor is driven by three-phase AC, six transformers of the above-mentioned one transformer are obtained in order to obtain the required six sets of mutually exclusive driver power supplies. A secondary winding for the power supply must be provided.

However, if one transformer is provided with a number of secondary windings corresponding to the required power supply for the driver, the weight of the transformer is increased. Is caused, and the number of connecting pins of the transformer is increased, so that the outer size of the transformer becomes large. Also, if multiple secondary windings are provided in one transformer, many connecting bins will be concentrated in that transformer, so the power supply line will be routed from the transformer position to the power supply position. There must be. In addition, The number of connecting pins for the transformer fixed to the printed circuit board is large, so the wiring of the printed wiring becomes complicated.In particular, when the output voltage is high, the spacing of the printed wiring is increased to prevent sparks. It is necessary to increase the size of the printed circuit board itself and increase the packaging density of the device. Disclosure of the invention

It is an object of the present invention to use a single switching control circuit and switching means to apply chopped voltage to multiple transformers at the same time, and to generate a plurality of isolated DC voltages. It provides a switching regulator that is suitable for print wiring.

According to the present invention, a power supply unit, a switching unit, a main power source transformer having a primary winding connected to the power supply unit via the switching unit, and a main power source transformer. A switching control circuit for detecting the output voltage of one of the secondary windings to control the duty ratio of the switching means, a switching control circuit inserted in the forward direction in series with the primary winding of the main power transformer. 1 diode, at least one secondary power supply transformer whose primary winding is connected in parallel with the primary winding of the mains power supply transformer described above, and said at least one secondary power supply transformer. A switch regulator is provided that includes a second diode inserted in series in each of the primary windings of the power transformer in the forward direction.

According to the switching regulator of the present invention, one switching control circuit and switching means are used at the same time. By applying the selected voltage to multiple transformers, it is possible to generate multiple DC power sources that are mutually isolated. By dividing one transformer with many windings into multiple small transformers, the weight applied to the printed circuit board can be equalized. In addition, the space occupied by the printed circuit board on which the transformer is mounted is minimized, and the printed circuit board itself is made smaller by simplifying the printed circuit board wiring to improve the mounting efficiency of the device. Can be improved. Brief description of the drawings

FIG. 1 is a block diagram showing a part of an embodiment of a switching regulator according to the present invention, and

Figure 2 is a block diagram showing the switching control circuit. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a circuit diagram showing a part of an embodiment of a switch regulator according to the present invention by a block, where 1 is a DC power supply, 2 is a switching transistor, 3 is a switching control circuit 4, 4 is a main power supply, 5 is a first driver power supply, and 6 is a second driver power supply.

DC power supply 1 is the output of a battery or a rectifier circuit, and its voltage E is connected in series via switching transistor 2 and diodes 45, 55 and 65 for cutting forward circulating current. Transformer in main power supply section 4 (transformer for main power supply) Primary winding line Ν _{4 1 of} T ₄ , transformer in 1st driver power supply section 5 Primary winding New ₆ power transformers) transformer in the primary winding ₅₁ and the second driver power section 6 of T ₅ (the sub power transformer) T _6, respectively adapted to be applied to ing. Here, multiple driver power supply units are connected. For example, when controlling three AC servomotors with three-phase AC, nine driver power supply units are connected in parallel. Become. The switching control circuit 3 controls the on-period ratio (duty ratio) of the switching transistor 2 by pulse width modulation (PWM), and this switching transistor is used. For ^ 2, for example, a fast-moving MOS FET is used because it is driven at a frequency of 40 KHz.

And the transformer T ₄ of the secondary winding New _{4 Zeta} and New ₄₃ to the secondary side and the control target power supply 2 Tsugimaki镍New _44, the main power supply 4 are provided, in each of the secondary windings The rectifying diode and smoothing capacitor that are connected are used to obtain the necessary DC power supply. Specifically, for example, the secondary winding Ν ₄₂ supplies the DC 24V used for the interface and the secondary winding Ν ₄₃ supplies the DC ± 15 V used for the analog differential amplifier. subjected lined, and the control target power for the secondary winding New ₄₄ is supplied to DC 5 V, which is used as a main power source of the speed control circuit that requires a large capacity. A part of the output voltage obtained from the secondary winding Ν ₄₄ for the power source to be controlled which is used as this main power source is fed back to the switching control circuit 3, and the switching voltage is converted to a constant voltage. The secondary side of the transformer Τ ₅ in the first driver power supply section 5, which is designed to control the transient signal of the transistor 2, is Secondary windings N ₅₂ and N ₅₃ and adjustment winding N ₅₄ are provided, and these windings are connected to a rectifying diode and a smoothing capacitor, respectively, so that the required DC power supply can be obtained. Has been done. Specifically, for example, the secondary windings N _{s 2} and N ₅₃ are each adapted to supply 7.5 V and 14 V DC required for one driver transistor, respectively. When controlling the AC servomotor with three-phase AC, for example, three driver power supplies' are required for one AC servomotor in order to use two driver transistors per phase. , in order to drive and control a three-phase AC three AC servomotor also Do that nine driver power supply unit are connected in parallel, the secondary side of the first driver power supply unit 5 definitive transformer T ₅ Is provided with an adjusting winding N ₅₄ whose number of windings is equal to the output voltage (for example, DC 5 V) of the controlled secondary winding N ₄₄ . A rectifying diode and a smoothing capacitor are connected to the adjusting coil wire N ₅₄ , and are connected to the output of the secondary winding N ₄₄ for the controlled object. As a result, the output voltage from the secondary windings N ₅₂ and N ₅₃ of the first driver power supply section 5 is made constant, and the load voltage of these secondary windings N _{5 z} and N ₅₃ is also reduced. When T is small, the energy of the transformer T ₅ is sent from the adjustment winding Ν ₅₄ to the output of the secondary winding Ν ₄₄ for the controlled power source.

The second driver power supply section 6 has exactly the same configuration as the first power supply section 5, and a secondary winding Ν ₆₂ and a secondary winding Ν ₆₂ are provided on the secondary side of the transformer Τ _&. / 7/00118

In addition, the adjustment winding N _{6 4} is provided to supply the regulated direct current voltage, and when the load on the secondary winding lines N _{6 2} and N _{6 3} is small, the transformer T ₆ Energy winding for adjustment

It is designed to be sent from Ν _{6 4} to the secondary winding Ν _{4 4} for the power supply to be controlled. In this type of driver, the power supply section is not limited to the first driver power supply section 5 and the second driver power supply section 6, but multiple driver power supply sections (for example, nine) are connected in parallel. As mentioned above.

These driver power supply units are fixed on the printed circuit board near the drive transistors, but the printer wiring required for each driver power supply unit is different for each transformer. Since only the wiring for connecting to the primary winding and adjustment winding of the converter is required, the printed wiring can be simplified and the printed circuit board itself can be downsized. In addition, by dividing the transformer to reduce the number of connecting pins of one transformer, the transformer can be miniaturized and the weight of the transformer can be distributed when it is fixed to the printed circuit board. In addition, one switching control circuit 3 and one switching transistor 2 can be applied to a plurality of transformers at different prices, which is advantageous in terms of price.

Figure 2 is a block diagram showing the switching control circuit 3. Controlled power supply in the main power supply section 4 (output of the secondary winding Ν _{4 4} for controlled power supply) and adjustment in the 1st driver power supply section 5 The output of the control winding N _{s 4 and} the output of the adjustment winding Ν _{6 4} (power supply Α) in the second driver power supply section 6 are fed back to the switching control circuit 3 and the power supply Α (for example, DC 5 V) is the comparison time In path 3 2 it is compared with a reference voltage 3 1 which is the voltage E _r (eg regulated DC 5 V). The output of the comparison circuit 3 2 is amplified by the amplification circuit 3 3 and sent to the photocatalyst 3 4. This photo coupler 3 4 is for floating the output of the amplifier circuit 3 3 in the previous stage.The output of the photo coupler 3 4 is amplified by the amplifier circuit 3 5 and input to the duty ratio control circuit 3 7. Will be added. The duty ratio control circuit 37 generates a signal having a predetermined pulse width from the sawtooth wave having a constant cycle generated by the sawtooth wave generation circuit 36 and the output of the amplifier circuit 35. As a result, the ratio of the ON period of switching transistor 2 to the cycle (duty ratio) is determined.

Next, the operation of one embodiment of the switching regulator according to the present invention will be described.

First, when the switching transistor 2 is turned on by the drive signal of the switching control circuit 3, the voltage E of the DC power supply 1 is transformed through the forward circulating current cutoff diodes 45, 55 and 6 δ. Applied to primary winding Ν ₄₁ of transformer Τ ₄ , primary winding Ν ₅₁ of transformer Τ ₅ and primary winding Ν ₆₁ of transformer Τ ₆ respectively. As a result, the secondary windings Ν ₄₂ and Ν ₄₃ of the transformer Τ _4, the secondary winding Ν _{44 of} the controlled power source, the secondary windings Ν ₅₂ and Ν _{53 of} the transformer Τ _{5 and} the adjustment winding Ν ₅₄ and the secondary windings Ν ₆₂ and Ν _{63 of the} transformer Τ ₆ as well as the adjusting winding Ν ₆₄ are respectively rectified by a positive voltage induced on the mark side, but rectifying diodes in the windings. Does not conduct because it is inserted in the opposite direction. In this state, power is supplied to the output side. There is no supply, but energy accumulates in transformer T ₄ , transformer T ₅ and transformer τ ₆ .

When the switching transistor 2 is cut off after a certain period of time, the polarities of the transformer Τ ₄ , the transformer Τ ₅ and the transformer Τ ₆ are reversed, and the secondary windings Ν ₄₂ and Ν _{43 are} turned on. Connected to the secondary windings Μ ₄₄ , the secondary windings Ν ₅₂ and Ν ₅₃ , the adjustment winding Ν ₅₄ and the secondary windings Ν _{6 Ζ} and Ν _{63 and the} adjustment winding Ν ₆₄ for the power supply to be controlled. The rectifying diodes are turned on, and the energy stored in the transformer Τ ₄ , the transformer Τ ₅ and the transformer Τ- ₆ is supplied to the smoothing capacitors and their respective output sides. The primary winding New ₆ ^ this primary winding New ₅₁ and the transformer T ₆ of the primary winding New ₄ have the transformer T ₅ of the transformer T ₄ are forward to each direct current power source 1 Since the circulating current cut-off diodes 45, 55 and 65 are inserted in the direction opposite to the current that flows when the switching transistor 2 is cut off, the transformer Τ ₄ , The energy stored in the transformer Τ ₅ and the transformer Τ '6 does not flow in the respective primary windings Ν ₄ i, N ₅ and N ₆ .

In this way, the main power supply unit 4, the first driver power supply unit 5 and the second driver power supply unit 6 can obtain a predetermined DC voltage according to the number of individual secondary windings. ..

In here, is a power supply A you return to the sweep rate etching control circuit 3 as described above, such only the output of the controlled object power supply secondary winding N ₄₄ of the main power supply 4 Ku first driver Since the output of the adjusting winding N ₅₄ in the power supply section 5 and the output of the adjusting winding N ₆₄ in the second driver power supply section 6 are also connected, the transformer T ₄ Not only can the output of the secondary windings N ₄₂ and N ₄₃ of the transformer be regulated, but also the output of the secondary winding N ₅₂ and N ₅₃ of the transformer T _{5 and} the secondary of the transformer T ₆ The outputs of windings N ₆₂ and N ₆₃ can also be made constant voltage. Furthermore, when the power consumed in the first driver power supply section 5 or the second driver power supply section 6 is small, the adjustment winding wire Ν ₅₄ or transformer Τ _{6 of the} transformer T ₅ is The extra energy in each of the adjusting windings Ν ₆₄ of each of the transformers is separately sent to the secondary winding Ν ₄₄ for the power source to be controlled. '"

As described above in detail, the switching regulator according to the present invention is chopped to a plurality of transformers at the same time by using one switching control circuit and the switching means. By applying a voltage and generating multiple DC power supplies that are mutually insulated, the size of the transformer can be reduced. The volume can be reduced and downsized, and it is also advantageous in terms of price.

Claims

The scope of the claims

1. power supply means,

Switching means,

A transformer for a main power supply, in which a primary winding is connected to the power supply means through the switching means,

A switching control circuit for detecting the output voltage of one of the secondary windings of the main power transformer and controlling the duty ratio of the switching means,

A first diode inserted in the forward direction in series with the primary winding of the main power transformer,

At least one secondary power transformer, whose primary winding is connected in parallel with the primary winding of said main power transformer, and

A second diode inserted in series in each of the following windings of said at least one auxiliary power transformer,

A switching regulator equipped with.

2. The at least one auxiliary power transformer is provided with an adjusting winding connected in parallel with one of the secondary windings of the main power transformer. Switching regulator described in paragraph 1.

3. The switching regulator according to claim 1, wherein the switching regulator is a power source for operating the NOR device.